Gr. H. F. Nuttall and S. Hadwen 
249 
The Effects of Trypanblau upon the Parasites. 
The most striking proof of the efficacy of the drug is, however, 
afforded by the obvious effect it exerts upon the parasites. Exactly as 
in P. cams, the (D) forms are the first to disappear, then the (PP) 
forms, only the rounded or irregular forms (0) persisting for a time, 
whilst the percentage of infected r.b.c. falls rapidly. The effects of try¬ 
panblau are clearly set out in the following tables and the charts on 
pp. 259 et seq. Cow 5 received the drug subcutaneously, which accounts 
for the slower effect exerted upon the parasites. 
Blood examination before treatment. 
Cow 
Maximum percentage 
of infected r.b.c. 
Maximum percentage 
of (D) forms 
1 
2 
3 
4 
5 
0-8 
1-0 
1-0 
0-6 
1-5 
8 
8 
11 
3 
6 
N.B.—In none of the treated animals did the number of infected corpuscles exceed 
T5 °/ 0 . In two out of four controls (see p. 240) no less than 4 - 6 °/ 0 and 5 °/ 0 of infected 
r.b.c. are recorded. In only one of the treated cows did the number of (D) forms attain 
11 °/ 0 . In three out of four controls, 13 °/o> 14 °/ n and 16 °/ 0 of (D) forms were recorded. 
These differences are attributable to the treatment. 
Table showing the effect of the drug in reducing the percentage of infected 
corpuscles ivithin 4^ to 8 hours after treatment and causing the disappear¬ 
ance of (PP) and (D) forms. 
infected r.b.c. (PP) forms (D) forms 
Percentage of Percentage of Percentage of 
Treated 
Cow No. 
Showing effect 
of drug after 
stated time 
had elapsed 
At time 
when drug 
was given 
After drug 
was given 
At time 
when drug 
was given 
After drug 
was given 
At time 
when drug 
was given 
After drug 
was given 
i 
4| hours 
0-8 
•01 
33 
i 
4 
0 
2 
8 „ 
1-0 
•03 
41 
i 
8 
0 
3 
4| „ 
0-6 
•06 
44 
2 
5 
0 
4 
4* „ 
0-6 
•03 
33 
3 
2 
0 
5* 
7 „ 
1-5 
•02 
33-5 
5’5 
4 
1 
* This ease was treated by subcutaneous injection. The effect of the drug is obviously 
less rapid. 
After the periods of time noted in the above table, the blood was 
repeatedly examined for parasites. The results of these examinations 
are summarized in the following table. 
